28 June 2010

New images of spillway at Attabad

Posted by Dave Petley

Unfortunately I cannot access images from Attabad at the moment, but the Pamir Times has this morning published a set that are well worth a look.  The images are here.  Interestingly, they also note that the water level has reduced by 13 inches (about 33 cm) over the last two days, which is a promising sign.  Unfortunately I cannot validate these figures at the moment.

The images seem to show that the key constraint remains the point of the large boulder as before, although the water has now eroded around this, leaving it stranded in the middle of the channel:

The channel is clearly widening on both sides through slope failures, increasing the capacity of the channel, but there is still remarkably little sign of down-cutting.  Meanwhile downstream, the dam is continuing to lose mass through erosion, a process that we must watch carefully:

This loss of volume is very slowly weakening the barrier.  There are no signs at the moment that this is a cause for real concern, but close monitoring is needed as the flow rate increases.